aboutsummaryrefslogtreecommitdiff
path: root/fs/ntfs/namei.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /fs/ntfs/namei.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'fs/ntfs/namei.c')
-rw-r--r--fs/ntfs/namei.c391
1 files changed, 391 insertions, 0 deletions
diff --git a/fs/ntfs/namei.c b/fs/ntfs/namei.c
new file mode 100644
index 000000000..4e6a44bc6
--- /dev/null
+++ b/fs/ntfs/namei.c
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * namei.c - NTFS kernel directory inode operations. Part of the Linux-NTFS
+ * project.
+ *
+ * Copyright (c) 2001-2006 Anton Altaparmakov
+ */
+
+#include <linux/dcache.h>
+#include <linux/exportfs.h>
+#include <linux/security.h>
+#include <linux/slab.h>
+
+#include "attrib.h"
+#include "debug.h"
+#include "dir.h"
+#include "mft.h"
+#include "ntfs.h"
+
+/**
+ * ntfs_lookup - find the inode represented by a dentry in a directory inode
+ * @dir_ino: directory inode in which to look for the inode
+ * @dent: dentry representing the inode to look for
+ * @flags: lookup flags
+ *
+ * In short, ntfs_lookup() looks for the inode represented by the dentry @dent
+ * in the directory inode @dir_ino and if found attaches the inode to the
+ * dentry @dent.
+ *
+ * In more detail, the dentry @dent specifies which inode to look for by
+ * supplying the name of the inode in @dent->d_name.name. ntfs_lookup()
+ * converts the name to Unicode and walks the contents of the directory inode
+ * @dir_ino looking for the converted Unicode name. If the name is found in the
+ * directory, the corresponding inode is loaded by calling ntfs_iget() on its
+ * inode number and the inode is associated with the dentry @dent via a call to
+ * d_splice_alias().
+ *
+ * If the name is not found in the directory, a NULL inode is inserted into the
+ * dentry @dent via a call to d_add(). The dentry is then termed a negative
+ * dentry.
+ *
+ * Only if an actual error occurs, do we return an error via ERR_PTR().
+ *
+ * In order to handle the case insensitivity issues of NTFS with regards to the
+ * dcache and the dcache requiring only one dentry per directory, we deal with
+ * dentry aliases that only differ in case in ->ntfs_lookup() while maintaining
+ * a case sensitive dcache. This means that we get the full benefit of dcache
+ * speed when the file/directory is looked up with the same case as returned by
+ * ->ntfs_readdir() but that a lookup for any other case (or for the short file
+ * name) will not find anything in dcache and will enter ->ntfs_lookup()
+ * instead, where we search the directory for a fully matching file name
+ * (including case) and if that is not found, we search for a file name that
+ * matches with different case and if that has non-POSIX semantics we return
+ * that. We actually do only one search (case sensitive) and keep tabs on
+ * whether we have found a case insensitive match in the process.
+ *
+ * To simplify matters for us, we do not treat the short vs long filenames as
+ * two hard links but instead if the lookup matches a short filename, we
+ * return the dentry for the corresponding long filename instead.
+ *
+ * There are three cases we need to distinguish here:
+ *
+ * 1) @dent perfectly matches (i.e. including case) a directory entry with a
+ * file name in the WIN32 or POSIX namespaces. In this case
+ * ntfs_lookup_inode_by_name() will return with name set to NULL and we
+ * just d_splice_alias() @dent.
+ * 2) @dent matches (not including case) a directory entry with a file name in
+ * the WIN32 namespace. In this case ntfs_lookup_inode_by_name() will return
+ * with name set to point to a kmalloc()ed ntfs_name structure containing
+ * the properly cased little endian Unicode name. We convert the name to the
+ * current NLS code page, search if a dentry with this name already exists
+ * and if so return that instead of @dent. At this point things are
+ * complicated by the possibility of 'disconnected' dentries due to NFS
+ * which we deal with appropriately (see the code comments). The VFS will
+ * then destroy the old @dent and use the one we returned. If a dentry is
+ * not found, we allocate a new one, d_splice_alias() it, and return it as
+ * above.
+ * 3) @dent matches either perfectly or not (i.e. we don't care about case) a
+ * directory entry with a file name in the DOS namespace. In this case
+ * ntfs_lookup_inode_by_name() will return with name set to point to a
+ * kmalloc()ed ntfs_name structure containing the mft reference (cpu endian)
+ * of the inode. We use the mft reference to read the inode and to find the
+ * file name in the WIN32 namespace corresponding to the matched short file
+ * name. We then convert the name to the current NLS code page, and proceed
+ * searching for a dentry with this name, etc, as in case 2), above.
+ *
+ * Locking: Caller must hold i_mutex on the directory.
+ */
+static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent,
+ unsigned int flags)
+{
+ ntfs_volume *vol = NTFS_SB(dir_ino->i_sb);
+ struct inode *dent_inode;
+ ntfschar *uname;
+ ntfs_name *name = NULL;
+ MFT_REF mref;
+ unsigned long dent_ino;
+ int uname_len;
+
+ ntfs_debug("Looking up %pd in directory inode 0x%lx.",
+ dent, dir_ino->i_ino);
+ /* Convert the name of the dentry to Unicode. */
+ uname_len = ntfs_nlstoucs(vol, dent->d_name.name, dent->d_name.len,
+ &uname);
+ if (uname_len < 0) {
+ if (uname_len != -ENAMETOOLONG)
+ ntfs_error(vol->sb, "Failed to convert name to "
+ "Unicode.");
+ return ERR_PTR(uname_len);
+ }
+ mref = ntfs_lookup_inode_by_name(NTFS_I(dir_ino), uname, uname_len,
+ &name);
+ kmem_cache_free(ntfs_name_cache, uname);
+ if (!IS_ERR_MREF(mref)) {
+ dent_ino = MREF(mref);
+ ntfs_debug("Found inode 0x%lx. Calling ntfs_iget.", dent_ino);
+ dent_inode = ntfs_iget(vol->sb, dent_ino);
+ if (!IS_ERR(dent_inode)) {
+ /* Consistency check. */
+ if (is_bad_inode(dent_inode) || MSEQNO(mref) ==
+ NTFS_I(dent_inode)->seq_no ||
+ dent_ino == FILE_MFT) {
+ /* Perfect WIN32/POSIX match. -- Case 1. */
+ if (!name) {
+ ntfs_debug("Done. (Case 1.)");
+ return d_splice_alias(dent_inode, dent);
+ }
+ /*
+ * We are too indented. Handle imperfect
+ * matches and short file names further below.
+ */
+ goto handle_name;
+ }
+ ntfs_error(vol->sb, "Found stale reference to inode "
+ "0x%lx (reference sequence number = "
+ "0x%x, inode sequence number = 0x%x), "
+ "returning -EIO. Run chkdsk.",
+ dent_ino, MSEQNO(mref),
+ NTFS_I(dent_inode)->seq_no);
+ iput(dent_inode);
+ dent_inode = ERR_PTR(-EIO);
+ } else
+ ntfs_error(vol->sb, "ntfs_iget(0x%lx) failed with "
+ "error code %li.", dent_ino,
+ PTR_ERR(dent_inode));
+ kfree(name);
+ /* Return the error code. */
+ return ERR_CAST(dent_inode);
+ }
+ /* It is guaranteed that @name is no longer allocated at this point. */
+ if (MREF_ERR(mref) == -ENOENT) {
+ ntfs_debug("Entry was not found, adding negative dentry.");
+ /* The dcache will handle negative entries. */
+ d_add(dent, NULL);
+ ntfs_debug("Done.");
+ return NULL;
+ }
+ ntfs_error(vol->sb, "ntfs_lookup_ino_by_name() failed with error "
+ "code %i.", -MREF_ERR(mref));
+ return ERR_PTR(MREF_ERR(mref));
+ // TODO: Consider moving this lot to a separate function! (AIA)
+handle_name:
+ {
+ MFT_RECORD *m;
+ ntfs_attr_search_ctx *ctx;
+ ntfs_inode *ni = NTFS_I(dent_inode);
+ int err;
+ struct qstr nls_name;
+
+ nls_name.name = NULL;
+ if (name->type != FILE_NAME_DOS) { /* Case 2. */
+ ntfs_debug("Case 2.");
+ nls_name.len = (unsigned)ntfs_ucstonls(vol,
+ (ntfschar*)&name->name, name->len,
+ (unsigned char**)&nls_name.name, 0);
+ kfree(name);
+ } else /* if (name->type == FILE_NAME_DOS) */ { /* Case 3. */
+ FILE_NAME_ATTR *fn;
+
+ ntfs_debug("Case 3.");
+ kfree(name);
+
+ /* Find the WIN32 name corresponding to the matched DOS name. */
+ ni = NTFS_I(dent_inode);
+ m = map_mft_record(ni);
+ if (IS_ERR(m)) {
+ err = PTR_ERR(m);
+ m = NULL;
+ ctx = NULL;
+ goto err_out;
+ }
+ ctx = ntfs_attr_get_search_ctx(ni, m);
+ if (unlikely(!ctx)) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ do {
+ ATTR_RECORD *a;
+ u32 val_len;
+
+ err = ntfs_attr_lookup(AT_FILE_NAME, NULL, 0, 0, 0,
+ NULL, 0, ctx);
+ if (unlikely(err)) {
+ ntfs_error(vol->sb, "Inode corrupt: No WIN32 "
+ "namespace counterpart to DOS "
+ "file name. Run chkdsk.");
+ if (err == -ENOENT)
+ err = -EIO;
+ goto err_out;
+ }
+ /* Consistency checks. */
+ a = ctx->attr;
+ if (a->non_resident || a->flags)
+ goto eio_err_out;
+ val_len = le32_to_cpu(a->data.resident.value_length);
+ if (le16_to_cpu(a->data.resident.value_offset) +
+ val_len > le32_to_cpu(a->length))
+ goto eio_err_out;
+ fn = (FILE_NAME_ATTR*)((u8*)ctx->attr + le16_to_cpu(
+ ctx->attr->data.resident.value_offset));
+ if ((u32)(fn->file_name_length * sizeof(ntfschar) +
+ sizeof(FILE_NAME_ATTR)) > val_len)
+ goto eio_err_out;
+ } while (fn->file_name_type != FILE_NAME_WIN32);
+
+ /* Convert the found WIN32 name to current NLS code page. */
+ nls_name.len = (unsigned)ntfs_ucstonls(vol,
+ (ntfschar*)&fn->file_name, fn->file_name_length,
+ (unsigned char**)&nls_name.name, 0);
+
+ ntfs_attr_put_search_ctx(ctx);
+ unmap_mft_record(ni);
+ }
+ m = NULL;
+ ctx = NULL;
+
+ /* Check if a conversion error occurred. */
+ if ((signed)nls_name.len < 0) {
+ err = (signed)nls_name.len;
+ goto err_out;
+ }
+ nls_name.hash = full_name_hash(dent, nls_name.name, nls_name.len);
+
+ dent = d_add_ci(dent, dent_inode, &nls_name);
+ kfree(nls_name.name);
+ return dent;
+
+eio_err_out:
+ ntfs_error(vol->sb, "Illegal file name attribute. Run chkdsk.");
+ err = -EIO;
+err_out:
+ if (ctx)
+ ntfs_attr_put_search_ctx(ctx);
+ if (m)
+ unmap_mft_record(ni);
+ iput(dent_inode);
+ ntfs_error(vol->sb, "Failed, returning error code %i.", err);
+ return ERR_PTR(err);
+ }
+}
+
+/**
+ * Inode operations for directories.
+ */
+const struct inode_operations ntfs_dir_inode_ops = {
+ .lookup = ntfs_lookup, /* VFS: Lookup directory. */
+};
+
+/**
+ * ntfs_get_parent - find the dentry of the parent of a given directory dentry
+ * @child_dent: dentry of the directory whose parent directory to find
+ *
+ * Find the dentry for the parent directory of the directory specified by the
+ * dentry @child_dent. This function is called from
+ * fs/exportfs/expfs.c::find_exported_dentry() which in turn is called from the
+ * default ->decode_fh() which is export_decode_fh() in the same file.
+ *
+ * The code is based on the ext3 ->get_parent() implementation found in
+ * fs/ext3/namei.c::ext3_get_parent().
+ *
+ * Note: ntfs_get_parent() is called with @d_inode(child_dent)->i_mutex down.
+ *
+ * Return the dentry of the parent directory on success or the error code on
+ * error (IS_ERR() is true).
+ */
+static struct dentry *ntfs_get_parent(struct dentry *child_dent)
+{
+ struct inode *vi = d_inode(child_dent);
+ ntfs_inode *ni = NTFS_I(vi);
+ MFT_RECORD *mrec;
+ ntfs_attr_search_ctx *ctx;
+ ATTR_RECORD *attr;
+ FILE_NAME_ATTR *fn;
+ unsigned long parent_ino;
+ int err;
+
+ ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
+ /* Get the mft record of the inode belonging to the child dentry. */
+ mrec = map_mft_record(ni);
+ if (IS_ERR(mrec))
+ return ERR_CAST(mrec);
+ /* Find the first file name attribute in the mft record. */
+ ctx = ntfs_attr_get_search_ctx(ni, mrec);
+ if (unlikely(!ctx)) {
+ unmap_mft_record(ni);
+ return ERR_PTR(-ENOMEM);
+ }
+try_next:
+ err = ntfs_attr_lookup(AT_FILE_NAME, NULL, 0, CASE_SENSITIVE, 0, NULL,
+ 0, ctx);
+ if (unlikely(err)) {
+ ntfs_attr_put_search_ctx(ctx);
+ unmap_mft_record(ni);
+ if (err == -ENOENT)
+ ntfs_error(vi->i_sb, "Inode 0x%lx does not have a "
+ "file name attribute. Run chkdsk.",
+ vi->i_ino);
+ return ERR_PTR(err);
+ }
+ attr = ctx->attr;
+ if (unlikely(attr->non_resident))
+ goto try_next;
+ fn = (FILE_NAME_ATTR *)((u8 *)attr +
+ le16_to_cpu(attr->data.resident.value_offset));
+ if (unlikely((u8 *)fn + le32_to_cpu(attr->data.resident.value_length) >
+ (u8*)attr + le32_to_cpu(attr->length)))
+ goto try_next;
+ /* Get the inode number of the parent directory. */
+ parent_ino = MREF_LE(fn->parent_directory);
+ /* Release the search context and the mft record of the child. */
+ ntfs_attr_put_search_ctx(ctx);
+ unmap_mft_record(ni);
+
+ return d_obtain_alias(ntfs_iget(vi->i_sb, parent_ino));
+}
+
+static struct inode *ntfs_nfs_get_inode(struct super_block *sb,
+ u64 ino, u32 generation)
+{
+ struct inode *inode;
+
+ inode = ntfs_iget(sb, ino);
+ if (!IS_ERR(inode)) {
+ if (is_bad_inode(inode) || inode->i_generation != generation) {
+ iput(inode);
+ inode = ERR_PTR(-ESTALE);
+ }
+ }
+
+ return inode;
+}
+
+static struct dentry *ntfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type)
+{
+ return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+ ntfs_nfs_get_inode);
+}
+
+static struct dentry *ntfs_fh_to_parent(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type)
+{
+ return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+ ntfs_nfs_get_inode);
+}
+
+/**
+ * Export operations allowing NFS exporting of mounted NTFS partitions.
+ *
+ * We use the default ->encode_fh() for now. Note that they
+ * use 32 bits to store the inode number which is an unsigned long so on 64-bit
+ * architectures is usually 64 bits so it would all fail horribly on huge
+ * volumes. I guess we need to define our own encode and decode fh functions
+ * that store 64-bit inode numbers at some point but for now we will ignore the
+ * problem...
+ *
+ * We also use the default ->get_name() helper (used by ->decode_fh() via
+ * fs/exportfs/expfs.c::find_exported_dentry()) as that is completely fs
+ * independent.
+ *
+ * The default ->get_parent() just returns -EACCES so we have to provide our
+ * own and the default ->get_dentry() is incompatible with NTFS due to not
+ * allowing the inode number 0 which is used in NTFS for the system file $MFT
+ * and due to using iget() whereas NTFS needs ntfs_iget().
+ */
+const struct export_operations ntfs_export_ops = {
+ .get_parent = ntfs_get_parent, /* Find the parent of a given
+ directory. */
+ .fh_to_dentry = ntfs_fh_to_dentry,
+ .fh_to_parent = ntfs_fh_to_parent,
+};